-<!-- $Id: introduction.xml,v 1.4 2001-10-24 09:27:59 adam Exp $ -->
+<!-- $Id: introduction.xml,v 1.5 2001-10-24 20:12:36 adam Exp $ -->
<chapter id="introduction"><title>Introduction</title>
<para>
- The &yaz; toolkit offers several different levels of access to the
- Z39.50 and SR protocols. The level that you need to use depends on
- your requirements, and the role (server or client) that you
- want to implement.
- </para><para>
- The basic level, which is independent of the role, consists of three
- primary interfaces:
+ The <ulink url="http://www.indexdata.dk/yaz/">&yaz;</ulink>
+ toolkit offers several different levels of access to the
+ <ulink url="http://www.loc.gov/z3950/agency/">ISO23950/Z39.50</ulink>
+ and <ulink url="http://www.nlc-bnc.ca/iso/ill/">ILL</ulink> protocols.
+ The level that you need to use depends on your requirements, and
+ the role (server or client) that you want to implement.
+ If you're developing a client application you should consider the
+ <link linkend="zoom">ZOOM</link> API.
+ It is, by far, the easiest way to develop clients in C.
+ Server implementers should consider the
+ <link linkend="server">generic frontend server</link>.
+ None of those high-level API's support the whole protocol, but
+ they support most facilities used in existing Z39.50
+ applications.
+ </para>
+ <para>
+ If you're developing non-standard extensions to Z39.50 or you're
+ going to develop an ILL application you'll have to learn the lower
+ level API's of &yaz;.
+ </para>
+ <para>
+ The basic low level modules, which is independent of the role,
+ consists of three primary interfaces:
<itemizedlist>
- <listitem><para>&asn;, which provides a C representation of the Z39.50/SR
+ <listitem><para>&asn;, which provides a C representation of the Z39.50
protocol packages (PDUs).
</para></listitem>
<listitem><para>&odr;, which encodes and decodes the packages according
</itemizedlist>
The &asn; module represents the ASN.1 definition of
- the SR/Z39.50 protocol. It establishes a set of type and
+ the Z39.50 protocol. It establishes a set of type and
structure definitions, with one structure for each of the top-level
PDUs, and one structure or type for each of the contained ASN.1 types.
For primitive types, or other types that are defined by the ASN.1
provided by the &odr; (Open Data Representation) subsystem.
</para>
<para>
- &odr; is a basic mechanism for representing an
+ &odr; is a basic mechanism for representing an
ASN.1 type in the C programming language, and for implementing BER
encoders and decoders for values of that type. The types defined in
the &asn; module generally have the prefix <literal>Z_</literal>, and
(passively or actively, depending on the role of your application),
and for exchanging BER-encoded PDUs over that connection. When you
create a connection endpoint, you need to specify what transport to
- use (OSI or TCP/IP), and which protocol you want to use (SR or
- Z39.50). For the remainder of the connection's lifetime, you don't have
+ use (TCP/IP or SSL).
+ For the remainder of the connection's lifetime, you don't have
to worry about the underlying transport protocol at all - the &comstack;
will ensure that the correct mechanism is used.
</para>
<para>
We call the combined interfaces to &odr;, &asn;, and &comstack; the service
- level API. It's the API that most closely models the Z39.50/SR
+ level API. It's the API that most closely models the Z39.50
service/protocol definition, and it provides unlimited access to all
fields and facilities of the protocol definitions.
</para>
projects / yaz-moved-to-github.git / blobdiff